The coude-type catheter, which has been known for many years, utilizes a curved and closed end. This facilitates the easy passage of the catheter, especially in males, through the urethra, by facilitating the bypassing of the sinus junctions, so that the catheter spontaneously enters the neck of the bladder. Commonly, the curved or elbowed end of the coude catheter tapers to a minimum width at its end.
Various types of coude catheters are known, including inflatable Foley-type catheters, as well as simple, noninflatable Robinson-style catheters comprising a single tubular member.
The prior art coude catheters have the disadvantage of being expensive to manufacture. Accordingly, though they are very desirable for use in self-insertion by a layman, for example to assist in urination on a routine basis, the expense of the catheters has inhibited their use.
Latex coude catheters are generally made by dipping on a mold which defines the curved end, as well as the rest of the catheter. Also, coude catheters have been made by casting the catheter tip in contact with the end of catheter tubing, so that the tip becomes a sealed end portion for a catheter tube. Polyvinyl chloride and plasticizer in a liquid form have been used for this purpose. The cure to solidification takes place by heating to form the final, joined, two-piece catheter.
Disadvantages of the above are found, in that it is difficult to obtain a smooth transition between the cast head and the body of the catheter without irregularities and the like, which are quite undesirable in a urinary drainage catheter. Also, a risk exists of separation of the cast head from the catheter body when inserted in the bladder.
By this invention, a molding technique is provided in which a single piece of thermoplastic, flexible tubing is converted into a catheter having a coude-type end without the use of a separate, cast piece, or without the laborous and time-consuming dipping technique, which requires multiple dipping steps to obtain the desired catheter.